Fuel control for combustion engines



Sep 1942; IR. HARTNER-SEBERKZH 2,297,217

FUEL CONTROL FOR COMBUSTIQN ENGINES Filed Feb. 11, 1939 Patented Sept. 29, 1942 UNITED, STATES, PATIENT orricr; 2.297.211 a Richard Hartner-Seberich, Gagg'enau, Baden, Germany; vested in the Allen Property Custodian.

Application February 11, 1939, Serial No. 255,977

In Germany February 4, 1937 11 Claims. I (Cl. 123-121) the gas-suction passage of Figure 1 at the point The invention relates to an improved fuel control for combustion engines, and is concerned with internal combustion engines, particularly for motor vehicles, operated normally with gas and from time to time with liquid fuel. In such engines, the suction passage for the carburetter opens into the suction passage for the gas-producer. Depending upon the setting of the con-' trol, the engine draws in either-gas or liquid fuel, advantageously gasoline, mixed with air. The closure members of the control, for example throttle flaps, in the known arrangements, are

where the carburetter passage branches.

The. suction passage I leading from the gas.

producer divides, before opening into the cylinders, into the usual branches I I and is secured to the engine housing by means of flanges 2 in known manner. A throttle valve 3 is provided infront of the branching of the gas-suction ment serves the purpose, on the one hand, of

- achieving an extraordinary increase of output by the operation withliquid fuel, when the gas operation is no longer sufflcient. On the other hand,

'the driver should be constrained to drive with additional gasoline not more frequently than is necessary. The arrangement described only solvesthis problem incompletely, because it does not exclude a misuse of the gasoline operation if the driver drives unnecessarily with gasoline and gas or does not ignite the gas producer at all, or allows the same to burn idly.

According to the present invention, the carburetter passage is arranged as a closed by-pass which branches from any desired point in the gas-suction passage and opens into it again as close as Possible to the inlet ports of the cylinders, the passage cross-section of the carburetter passage being made so narrow, or the carburetter being made so small, that the operation with liquid fuel permits only of an idle-running maxi-.

mum speed of revolution.

In the arrangement according to the inventhe kindling of the generator and for starting,

, tion, a maximum output can be achieved only 4 but otherwise is made so small, including the quantity of liquid fuel which is readily available ,that the driver does not even attempt to drive with liquid fuel longer than is necessary.

The invention is illustrated diagrammatically in the drawing in one embodiment by way of examplei Figure 1 isa sectional elevation of an engine having a gas-suction pipe serving-four cylinders I together with the carburetter passage arranged thereon: and

'Figure 2 is a cross-section and inverted plan of pipe I. This throttle 3 is connected to suitable control means such as a pedal as shown in the drawing, and serves for the normal control of the quantity of air-gas mixture flowing to the engine.

I, the opening of the by,-p'ass arms 4 4 taking place directly in front of or beyond the opening of the branches ll, I of the suction pipe into the engine. Preferably the pipes 4 4 are extended,

within the branches I I, to points directly infront of the inlet ports of the cylinders. A carburetter 5 for liquid fuel is included in the by- I pass 4 and a throttle valve 6 is provided beyond the carburetter jet as control means for the quantity of carburetter mixture. Liquid fuel is supplied to the carburetter through the pipe I. A second valve 8 is arranged in the gas-suction pipe I beyond the branching of the by-pass 4. This throttle 8 as a change-over throttle for the change-over of the arrangement from operation with gaseous fuel to operation with liquid fuel or vice versa. Opposite to the point of branching of the passage 4 and at the same level, there opens into the suction pipe I an air connection 9 which has a somewhat larger passage 'crosssection than the passage 4 and is closable by a throttle flap III. The axes of the pipes 4 and 9 do not intersect the axis ofthe pipe I but are offset in relation thereto -in such fashion that the air connection 9 opens tangentially into the pipe I and the passage 4 branches tangentially (Fig. 2). In the example illustrated, the throttles 3 and 6 are seen to be under independent control by separate pedals, and the throttles 8 and Ill are seen to be under independent control by separate hand levers. i

The manipulation and manner of operation of the arrangement are as follows: All of the throttle valves move independentlyof one another. The kindling of the gas producer and starting are effected with liquid fuel. The valves 3, 8 and ID are closed and the throttle 6 is opened.

The suction-pipe space beyond the valve 8 is cut of! from the suction action in the passage 4 by the said valve 8 and the air for carburation is taken from the passage leading from the gas producer, which in turn increases the draft in the gas producer and facilitates its kindling. The control of the quantity of carburetter mixture is effected by the throttle 6. As soon as the gas producer supplies suflicient gas to permit of the commencement of gas operation, the valves 8 and 3 are opened, whereupon the suction of the engine acts in the passage I because its resistance to flow is lower than that of the passage 4. The control of the quantity of the gas supply is eifected by the throttle 3, whilst the valve 8 merely controls the degree of change-over from gas operation to liquid operation or vice versa.

With both modes of operation, more ,or less fresh air may .be supplied directly both to the carburetter and also to the gas-producer mixture by adjusting the valve In. Primarily, however, the valve It! serves for mixture control in the case of gas operation. By reason of the fact that the air connection 9 opens tangentially into the pipe I, the air entering through this connection imparts a rotatory motion to the gas-flow passing through the pipe I in the direction of the arrow, but without considerable pressure losses being caused by sudden changes of compression. .The valve 8 arranged beyond the mouth of the connection 9, intersects the rotating gas flow o'n a helical line and thus facilitates,

by intensive turbulence, the mixture of the gas and air. Preferably, beyond the point of entry of the fresh air into the passage l, for example in front of the valve 8, there is introduced a screen or gauze H which serves as a gas and air filter and as a safety device for preventing the striking back of flame.

As already mentioned, the cross-section of. the passage 4 is made so narrow, or the carburetter is made so small, that an idle-running output only can be achieved with liquidoperation. A further precautionagainst misuse of the liquid operation can be provided by keeping the fuel vessel, which supplies the carburetter with liquid fuel, very small. This prevents the driver from driving for a considerable time with liquid and gas.

Making the carburetter output small also reliably prevents the running of the engine to destruction. Furthermore, the narrow carburetter passage results in a very high flow velocity and thereby avoids the formation of condensate. This is also avoidedin the engine in front of the inlet valves because the branches of the carburetter passage are carried inside the wide gasas supp y,

said gas supply, a second conduit provided with one or more branches at one end within said gas manifold for direct communication with said cyl inders, and communicating at its other end with said first conduit intermediate said manifold and and'means bureter.

for supplying liquid fuel to said car- 2. The combination according to claim 1, in

combination with a pair of adjustable throttle valves in said first conduit intermediate the communication with said second conduit and said manifold, one of said valves being positioned directly in front of the interconnection within said manifold.

3. The combination according to claim 1, wherein the size of said second conduit and the size of said carbureter therein are socorrelated pipe branches into close proximity to the inlet.

ports. 3 Instead of the independent controls illustrated, an appropriate coupling of the throttle valves can be effected, but the advantage of the inven: tion is achieved when the controls of the throttle valves are independently actuated levers.

It will be seen therefore that I have provided a device which fulfills theobjects primarily stated, and while I have shown a single embodiment of my invention, it is clear that other forms thereof may readily be provided without means with the size of said engine as to supply at their maximum an amount of fuel suflicient merely for idling of said engine. 1 p

4. The combination according to claim 1, in

combination with a back-fire screen in said first conduit intermediate said manifold and the communication with said second conduit.

5. The combination according to claim 1, in which said second conduit is connected tangentially with said first conduit.

6. The combination according to claim 1, in which said second conduit is connected tangenv tially' with said first conduit,in combination with an air induction pipe connected tangentially to said first-conduit on the opposite side of the connection with said second conduit.

7. The combination according to claim 1, in

which said second conduit is connected tangenfirst conduit. in combination with tially with said an air induction pipe connected tangentially to said first conduit on the opposite side of the connection with said second conduit, and an adjustable air valve in said air induction conduit.

8. In an internal combustlm engine, in combination, a gas producer, means for connecting said producer to said engine including a. first conduit, a source of liquid fuel, a second conduit substantially smaller than said first conduit connected at one end to'said engine and at its other end to said first conduit intermediate said gas pro-' ducer and said engine, a carbureter in said second conduit for supplying liquid fuel to said engine, and valve means for controlling the flow of the gas and liquid fuel.

9. Combination according to claim 8, in which said second conduit is connected substantially tangentially to said first conduit.

10. Combination according to claim 8, in which said second conduit is connected substantially tangentially to said first conduit, in combination with an air inductionpipe connected tangentially to said egst conduit directly opposite to the connection with said second conduit, and valve or controlling the air in said induction including a carbureter, means for connecting said producer and said source for supplying said fuel to said engine, and adjustable means for supplying air to said carbureter through said gas producer when said engine is being supplied with llqllld fuel, whereby thedraft in said gas producer is increased.

RICHARD HARTNER-SEBERICH.

a carbureter in said second conduit.

an internal combustion engine, in'combination, a gas producer, a source of liquid fuel 

